Hynek publishes the Close Encounters classification

In his book 'The UFO Experience: A Scientific Inquiry' Hynek introduces what becomes the enduring classification: Close Encounters of the First Kind (sighting under 150 m), Second Kind (physical traces), Third Kind (beings visible). The book breaks with the debunker stance: Hynek demands open, scientific investigation. The classification becomes the global standard in ufology and later the title of Spielberg's worldwide hit.